Share the small helpers procedures repeated

[jadamcrain]

Item 8 of #59.

Changes

• Trivial steps. TestStep(description)(act) builds a step that does one thing and defers no checks. It replaces the TestStep blocks written out for each such step. The description is still evaluated each time it's used.
• Plugin actions. PluginSteps.action is now shared. The procedures that wrote their own version use it, and 3.1r1's 8.24 uses PluginSteps.setFlagsNormal. Network's set-up and restore steps aren't changed, because they close the connection first.
• Level 1 tests. 3.1r1's 8.14.2-1 is now StaticInputs.LevelOneWithoutReads for events, with its own text for the last step. It was a copy of that class.
• Count-qualifier tests. The four count-qualifier event tests share their steps through EventTest.countReads. Each test still gives the step numbers its text uses. That sharing stays within 3.1r1, as the issue's "Not doing" list asks.
• IIN checks. IIN.objectErrors is the IIN2.1-or-IIN2.2 check, defined once. IIN.errors replaces the masks that also count IIN2.0.
• Result files. ResultFiles names the files a run writes.
• Saved results. SavedResult holds a procedure's ProcedureOutcome as it was saved, in place of TestResult. The file's format is unchanged, so existing results still read.
• Range headers. ObjectHeader.startStop builds a start/stop header without objects.

Checks

• -describe dump. I compared a dump of both revisions' trees, every procedure's -describe output, the disabled lists and Revision.validate, at each subset level, before and after. It's identical except for 3.1r1's 8.24 step that sets the flags normal. That step now says what normal is: "ONLINE set, all others clear".
• Protocol corpus. The seeded protocol parse corpus is unchanged.
• Tests. mvn test passes.